Lots of criticism of the short export window, but no one knows how many customers they have. Quill was early stage, trying to get into a competitive market, and they've exited in what looks like an acquihire. From this I'd interpret that they had low enough traction that the business couldn't continue. They may only have 10s of active teams, and it's fairly possible that they are in good contact with all of them and helping them do manual exports.

>> Can I export my team’s Direct Messages (DMs)? > No, we do not allow the export of Direct Messages.

As for this, this is very much in the "feature" category rather than the "bug" category. As much as communication on a company provided platform may not have a reasonable expectation of privacy, people still use these chats for private communication that they don't necessarily want all their coworkers knowing. Well done to Quill for taking this design approach. It may not even be technically possible if they're doing E2E encryption with DM participants.